You also studied here. Me, too. You can find the answer in several ways: you can go to Dangdang to buy an answer book; There is a question-and-answer online search answer; Or you can read more books, take notes in class, and see the answers at the back to push off your grades; If you really can't, just wait for the teacher to tell you.

There is also a message for you. If you study this major, you must learn this course well, otherwise you will not understand it in the future.